The present invention relates generally to disposable undergarments, and in particular, to a three-piece undergarment having a folded crotch member and to the method for the manufacture thereof from a nested front and rear body panel web.
Disposable undergarments can be configured in many different forms. For example, disposable absorbent garments can be configured as a pant-type, pull-on garment, or as a diaper-type product that is drawn up between the legs and fastened about the waist with various fastening systems. Often, absorbent garments include an outer cover, which forms at least a part of a body panel that is secured around the waist of the user. In addition, the outer cover typically extends along a crotch region of the garment.
Often, the outer cover is made from a single piece of material, with leg openings cut therein, for example by die cutting. The material from the leg cut out, which can account for as much as 20-30% of the total area of the outer cover, typically is waste material, which must be disposed of or recycled. In addition, the size of the leg openings formed by a die cutter in a conventional one-piece outer cover is typically fixed. As such, it can be expensive and time consuming, and reduces the overall flexibility of the manufacturing line, to switch dies and alter the process to manufacture different size garments.
In response to this problem of waste, some garments are configured with front, rear and crotch sections formed from a single web that is divided into two nested halves, as disclosed for example in U.S. Pat. No. 5,858,151 and Japanese Patent Application 03-176053 A. However, the webs of the U.S. Pat. No. 5,858,151 have overlapping crotch portions that are directly secured one to the other. Accordingly, the overall rise of the garment is not readily varied to accommodate different size users, and the range of sizes is limited by the extent of the overlapping regions.
Conversely, the diaper body of Japanese Patent Application 03-176053 A is positioned over the cut-out portions of a front and back waistband, such that the exposed portion of the waist bands defining in part the leg holes are linear. Instead, the shape of the leg hole is determined by the cut shape of the diaper body, which produces excess material that must be disposed of or recycled.
In addition, crotch members are often secured to the bodyside of the body panels or integrated therein, rather than being secured to the garment side thereof. Accordingly, the body panels can restrict the expansion of the crotch member, for example when an absorbent insert is insulted by the user.
U.S. Pat. Nos. 6,217,563 and 6,264,641, the entire disclosures of which are hereby incorporated herein by reference and which are both assigned to Kimberly-Clark Worldwide, Inc., the Assignee of the present application, disclose securing an expandable absorbent composite to a garment side of a pair of spaced apart body panels. The '563 and '641 patents disclose that the inboard edges of the body panel are straight or curved, and in one particular arrangement are concave-inward.
In addition, the crotch member, which is often configured as an absorbent insert, is typically not stretchable. Often, the non-stretchable crotch member is secured across its entire width, so as to reduce or otherwise impede the elongation of the body panel and thereby adversely affecting its ability to conform to the body of the user.
Therefore the need remains for improved methods and assemblies for manufacturing undergarments to reduce the waste of materials while providing improved comfort for the user and flexibility in manufacturing different size garments.